A general method for the preparation of zirconocene complexes of substituted benzynes: in situ generation, coupling reactions, and use in the synthesis of polyfunctionalized aromatic compounds

S. L. Buchwald, Watson, B. T. , Lum, R. T. , and Nugent, W. A. “A general method for the preparation of zirconocene complexes of substituted benzynes: in situ generation, coupling reactions, and use in the synthesis of polyfunctionalized aromatic compounds”, J. Am. Chem. Soc., 1987, 109(23), 7137-7141.
Abstract:

A general method for the in situ production of zirconocene complexes of substituted benzynes is reported. These complexes can be trapped with nitriles to form good yields of metallacyclic compounds with extremely good regiochemical control. These compounds can be converted into ketones, α-iodo ketones, and isothiazoles by using experimentally simple procedures. In addition, generation of the benzyne complexes under 1 atm of ethylene produces metallacycles which can be readily converted into the corresponding benzocyclobutanes.